Adjustable mitering square



J. E. GORDON 2,917,831

ADJUSTABLE MITERING SQUARE Filed Feb. 7, 1957 4 INVENTOR. l Jam f 60/200United 1 States Patent 2,917,831 ADJUSTABLE MITERING SQUARE John E.Gordon, Seattle, Wash. Application February 7, 1957, Serial No. 638,748

2 Claims. (CI. 33-40) This invention relates to construction tools andmore particularly relates to an adjustable mitering tool to facilitateready and easy marking of building rafters and the like.

An object of my invention is to provide a new and improved tool ofsimple and inexpensive construction and operation for setting and layingout the angles at which the end of a rafter is to be cut.

Another object of my invention is the provision of a novel hand tool forsetting the angles at which a rafter is to be cut and which tool may bequickly and accurately applied to such a rafter board so as tofacilitate marking of cut lines thereon.

A further object of my invention is to provide an improved adjustablemitering square for setting the angles at which rafters and the like arecut and which may be quickly and accurately applied to a rafter boardfor marking the cut lines even though the board may be slightly out ofsquare.

These and other objects and advantages of my invention will more fullyappear from the following description made in connection with theaccompanying drawings wherein like reference characters refer to thesame parts throughout the several views and in which:

Fig. 1 is a perspective view of the mitering tool applied to a rafterboard which is shown in dotted lines;

Fig. 2 is an elevation view of the tool positioned so that two of theouter surfaces are visible;

Fig. 3 is a detail transverse section view taken on a plane indicatedsubstantially at 3-3 of Fig. 2;

Fig. 4 is a detail transverse section view taken on a plane as indicatedsubstantially at 4-4 in Fig. 2; and

Fig. 5 is an elevation view showing a rear side of the invention notshown in Fig. 1.

The tool comprising the present invention is primarily adapted fordefining and laying out the angles at which the ends of rafter boardsand the like are to be cut in relation to the side surfaces of suchboards. The mitering tool includes an elongated body member which has agenerally rectangular cross section and which may be constructed of anysuitable rigid material such as wood, molded plastic or the like. Thebody member 10 is provided with at least a pair of outer surfaces 11 and12 which lie in planes that are perpendicular to each other. Surface 11provides a planar surface bearing which is to be laid against one of theside surfaces of the rafter board B shown in dotted lines in Fig. 1. Theforward portion of surface 12 defines a linear marking edge 13 whichlies substantially in the plane of the surface bearing 11. The bodymember.10 has an elongated slot 14 therein extending along the markingedge 13. The slot 14 is disposed at a forty-five degree angle withrespect to each of the surfaces 11 and 12 and, as best seen in Fig. 2,the slot 14 opens through the rear portion of the body member 10 at 15and 16.

[Asupporting member or projecting portion 17 is atfixed. Ion the upper;portion of the boar m m e and projects outwardly from the bearingsurface 11. 'The supporting member 17 has a downwardly facing Edge 20intersects the surface 18 at a point which may arbitrarily be termed ahook point which comprises the center of swinging movement of thesurface 11 and the body member 10 when the body member is supported bythe edge 20 on a rafter board. It will be noted that edge 20 lies in.two planes which are perpendicular to surface 11, one plane beingparallel to marking edge 13 and the other plane being perpendicular tothe marking edge 13.

An adjustable blade 21 is swingablymounted in the groove 14 and has aninner linear edge 22 which is contiguous to the marking edge 13 of thebody member to define miter cut angles therebetween. A pivot 23 issecured on the body member at the rear end portion of the groove 14 andin the opening 16 thereof. The blade 21 has an inner end portion 24which is notched at 25 to receive the pivot 23 therein. An arcuateguideway or groove 26 is formed in one of the walls of slot 14 and isgenerally circular in shapeabout the pivot 23. A guiding element or pin27 is affixed to the inner end portion of plate 21 and is carried in thegroove 26 to be guided thereby 23. j j

Pivot 23 defines the point about which plate 21 swings and pivot 23 isdisposed in a plane which is perpendicular to the surface 11 andparallel to marking edge13) and which plane includes the supporting edge20 and the hook point defined thereby.

The blade 21 is swingable from the position shown in Fig. 2, wherein theedge22 is perpendicular to the marking edge 13, to positions where theedges 22 and 13 define acuteangles and is further swingable inwardly.into slot 14 which substantially completely houses blade; 21 and therebypermits the tool to fold into small corn pass. When the edge 22 isdisposed normal to the marking edge 13, the edge 22 and surface 18 andsupporting edge 20 lie in a common plane which is per pendicular tosurface 11 and marking edge 13.

A stop 28 is formed in the body member 10 at the upper end thereof forengaging an abutting surface 29 of blade 21 to restrict upward swingingmovement there- I of beyond the position of blade 21 wherein edges 22and 13 are perpendicular to each other.

A thumb-receiving recess 30 is provided in surface 11 adjacent slot 14to facilitate ready and easy gripping of blade 21.

A pair of elongated scale members 31 and 32 are mounted on the surface33 of body member 10. The elongated scale members 31 and 32 have scales31a and 32a thereon which may be marked off in any suit- Member 31 isaffixed to the body member 10 as by screws 34. Member 32 Y is. swingablymounted on pivot screw 35 which is se cured to the body member 10 andwhich extends through I a suitably provided aperture in the scale member32. Scale member 32 is provided with a circular head portion 36 aroundthe pivot screw 35 and a scale 37 marked L off in degrees is providedaround the periphery thereof to, facilitate determining the anglebetween swingable blade 32 and fixed blade 31 orthe edge of surface331.2 of body member 10. Scale, member 32 may be swung:

able dimensions such as inches.

2,917,831 Patented Dec. 22, was

as the plate is swung about pivot 3 into end-to-end relation and linearalignment with scale member 31 as shown in the dotted position C in Fig.5 to facilitate measuring along the scales 32a and 31m.

Means are provided for presettingthe position of blade 21, dependentupon the slope of the roof for which the rafters to be cut are to beused. In the form shown such means include scales 38 and 39 onthesurfaces 11 and 12' respectively and along theedges of slot 14. One ofthe scales such as scale 38 may be marked for the angle at which blade21 is to be set for the marking of jack and common rafters. The otherscale such as. 39 may be graduated for the positions of blade 21 in themarking of hip rafters. 1

In the operation of the tool, the position ofthe blade will. be. set inaccordance with the graduations of the sc 'a'le dependent upon the typeof. rafters to be cut. For instance, if common rafters are tobe cut, theblade will be positioned in accordance withscale 38. When the blade 21is set in its desired position, thebody member is placed against theside surface of-the rafter board with the surface bearing 11 engagingthe rafter board. The supporting edge 20 will be hooked over the cornerof the rafter board and will engage the adjacent surface. The bodymember 10 will then be swung about the axis defined by thesup'portingedge 20 until blade 21 engages the top surface of the rafterboard. Provided that the adjacent surfaces of the rafter board aresubstantially perpendicular to each other, the marking edge 13 on thebody member 10 and the edge 21 of blade 21 will both engage therespective surfaces of the rafter board along their entire lengths tofacilitate ready and easy marking of the rafter board. When thedescribed operation is used, it is substantially impossible toinaccurately place the blade edge 22 and marking edge 13 on the rafterboard so as to define improper angles. When the blade edge 22 and themarking edge 13 engage the rafter board, these edges may be moved alongthe rafter board slightly to facilitate positioning of the angle cutlines at the proper position along the length of the board. If commonrafters are to be cut a mark may be made only along the. marking edge 13because the end surfaces of common rafters are generally disposed atright angles with the side surfaces of the rafter board and aregenerally disposed at acute angles with the top surfaces of the rafterboards.

If jack rafters are to be cut, the rafter board will also be" -markedalongthe blade-edge 22 to facilitate cutting of the jack rafters atangles with both the top and side surfaces thereof.

In cutting hip rafters, the position of the blade will be' determined inaccordance with the scale 39 which is graduated for hip rafters and therafter board will be marked along both of the edges 13 and 22.

The tool comprising the present inventionis also readily adapted formarking the rafter board for cutting of the wall seat therein where therafter rests upon the upright wall of a building. It should beremembered that normally, a triangular section must be cut out of thebottom surface of the rafter board to form this wall seat and thesection cut out will be shaped as a right triangle. One of the legs ofthis triangle willbe substantially vertical and this leg of the trianglewill be marked on the rafter board by sliding the tool along the boardas shown in position 1 and then marking the line along the marking edge13. The other leg of the triangle which is to be cut, will be disposedsubstantially horizontally to rest upon the top of the building wall.This horizontal leg of the triangle is marked by laying the bearingsurface 11 of the body member 10 againstthe bottom surface of the rafterboard and the supporting edge Ztland the blade edge-22 will engage theupright sidesurfaceof the rafter board whichwas previously engaged'bythe'body member? bearing surface 11. Th'e tw'o sides of the triangleSection. to becut' will. then be properly oriented with Pect.tcteach-other-anct-withthe bottomisuriate of th rafter board B and thedepth of the recess formed by the triangular cut need only be measuredbefore the horizontal leg of the triangle is marked.

in performing this operation of marking the rafter board, the adjustmentof the blade 21 remains unchanged after having marked the upper end ofthe rafter board which engages the ridge board of the buildingconstruction. In properly positioning the body member and blade on therafter board for making these marks for the wall seat the utilization ofthe supporting edge 20 in properly positioning the marking edges 13 and22 is as important as in making the marks for the miter cut at the upperend of the rafter board. The bearing surface 11 of the tool is againapplied toone of the rafter board surfaces and the supporting edge 20 ishooked over the rafter board and the body member and bearing surface 11will then be swung about edge 20 until the blade edge 22 engages therafter board.

it will be seen that I have provided a new and improved tool for quicklyand accurately setting and laying out miter cuts which are to be made ina rafter board or the like and when the tool is used in the methodspecified, the marking edges of the body member and blade will engagethe rafter board along their respective entire lengths. f

it should also be apparent that I have provided a novel tool of simpleand inexpensive construction and operation which is particularly welladapted for marking the miter cuts in a rafter board or the like whichis slightly out of square by placing the supporting edge of the toolupon one of the acute angledacorners of the rafter board andtnenoperating the tool in the specified manner, the result beiug'thatthe outer end portion of the blade edge may be slightly elevated fromthe adjacent surface of the rafter board,.but the setting. of the angleto be cut will be as accurate as is possible.

It will, of course, be understood that various changes may be made intheform, detail, arrangement and proportion of the parts withoutdeparting from-the scope of my invention which consists of the matterdescribed herein and set forth in the appended claims.

What is claimed is:

1. In a mitering tool, a body member. having means lying in a plane anddefining a surface bearing, said body member having a linear markingedge'intheplane of said bearing, a pivot on said-body member, a.- bladeswingably mounted on said pivot for movement. in a plane whichintersects the plane of the surface hearing at forty-five degrees along.said linear edge, said blade having an inner linear edge contiguous tosaid linear marking edge to form different angles therewith, and meanson said body member defining a" supporting edge extending outwardly fromand normal to said surface bearing and lying in a plane which passesthrough the pivot and which lies perpendicular to the plane of thesurface bearing, whereby said surface bearing may be placed upon asurface ofa rafter board or the like with said supporting edge engagingan adjacent surface of the board and'the body member may then be swungabout said edge to engage the board and thereby facilitate marking ofthe board at the desired angles along' said linear marking edge andinner linear edge.

2. In a tool for laying out miter cut angles on rafter boards and thelike comprising a body member having means defining a planar surfacebearing for engaging a surface of a rafter board, said surfacebearinghavinga forward portion and also having a rearportion, said-bodymember defining a marking edge in the plane of said bearing, a bladeswingably mounted on the upper end portion of the body member and havinga linear inner. edge-contiguous to said-marking edge, saidv blade swinging in aplane Whichintersects the plane ofithe surface' bearing alongsaid marking edge and being adjustab'lef be--' tween positions whereinsaid edgesare normalto? each other and wherein said edges define a'nacute ang1e;.-

body member having a projection on the upper end portion thereofextending outwardly from the surface bearing and defining downwardlyfacing and rearwardly facing surfaces which intersect at a supportingedge, said supporting edge lying in a plane which extends normal to thesurface bearing and normal to said marking edge and which plane alsoincludes the blade edge when the same is disposed normal to the markingedge, whereby the supporting edge and the surface bearing engageadjacent surfaces of the rafter board and the supporting edge defines aswing axis about which the body member is moved until the blade engagesthe rafter board.

References Cited in the file of this patent UNITED STATES PATENTS MabyeJuly 14, 1891 Callahan Dec. 2, 1902 Benskin Oct. 18, 1904 Johnson Jan.8, 1907 Galford Jan. 19, 1937 Tracy Aug. 20, 1940 Smith June 30, 1942Witter Jan. 25, 1944

